Disc brake for a commercial vehicle and brake pad set

ABSTRACT

A disc brake has a brake caliper, which reaches over a brake disc, is designed as a sliding caliper, is fastened to a stationary brake bracket and has a central opening over the brake disc. Two brake pads, which are arranged in the brake caliper and can be moved in opposite directions each have a backing plate and a friction lining fastened thereto. An action-side brake pad can be pressed against the brake disc by an application device by way of at least one brake piston. At least one restoring device is provided, by which the brake caliper can be returned after displacement and release of the brake caused by braking, wherein the restoring device has a spreading device, which acts on the brake pads lying opposite each other and acts in the same way against each particular application direction and has resilient spreading elements that act on the respective backing plates. The spreading device is arranged in the central opening, wherein the spreading elements act directly or indirectly outside of the friction linings on one side in the center region or at least two contact regions of the brake pads arranged at a distance from each other with respect to the center, wherein the contact regions each have a contact surface and a bearing surface, on which the spreading elements are movably arranged.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of PCT International Application No.PCT/EP2016/063594, filed Jun. 14, 2016, which claims priority under 35U.S.C. § 119 from German Patent Applications Nos. 10 2015 109 540.8,filed Jun. 15, 2015, 10 2015 117 285.2, filed Oct. 9, 2015, and 10 2016104 970.0, filed Mar. 17, 2016, the entire disclosures of which areherein expressly incorporated by reference.

BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates to a disc brake for a commercial vehicle as perthe preamble of claim 1. The invention also relates to a brake pad set.

In the case of a generic disc brake, also known as a sliding-caliperbrake, in a braking situation, an action-side brake pad is pressedagainst a vehicle-side brake disc by way of an application device, whichis actuable pneumatically or by electric motor. During the furthercourse of the braking process, the brake caliper is, relative to thebrake disc, displaced counter to the application direction of theaction-side brake pad, causing the opposite, reaction-side brake pad tobe driven along and pressed against the other side of the brake disc.

In the case of the known disc brake, after a release of the brake, thebrake caliper remains in said position, in which the brake pads, or atleast the reaction-side brake pad, lies against the brake disc dulywithout pressure but with a rubbing action. The residual rubbing torquesof the brake pads that thereby arise during driving operation have adisadvantageous effect because they lead to increased fuel consumptionand to a reduction of the service life of the components involved,specifically of the brake disc and of the brake pads.

It is duly the case that the brake pads are released slightly duringdriving operation for example as a result of a wobbling movement of thebrake disc and as a result of vibrations and lateral accelerationsduring cornering. These effects are however not sufficient to preventsaid residual rubbing torques in an effective manner.

To counteract this problem, the generic DE 10 2007 001 213 discloses adisc brake having a resetting device which is arranged in one of theguide beams by way of which the brake caliper is displaceably held onthe brake carrier, which resetting device has a resilient resettingelement by means of which the brake caliper is displaced into an initialposition.

This construction has proven successful in principle. However, the useof said known resetting device can lead to problems in the case ofcompressed-air-actuated disc brakes of heavy commercial vehicles,because here, there are wide-ranging influences resulting from componenttolerances and component deformations, which have the effect thatreliable functioning of said resetting device is not permitted in allsituations.

Similar problems arise in the case of a disc brake such as that to whichDE 10 2012 006 111 A1 relates. Here, a resetting device is arranged onthe side which is situated opposite the application device and whichfaces toward the reaction-side brake pad, whereby effective, inparticular automatic resetting of the brake caliper is realized, with asimultaneously minimal effect on the system rigidity.

In any case, the resetting device acts on the brake caliper, wherein thebrake carrier functions as a counterbearing.

DE 43 01 621 A1 describes a floating-caliper disc brake having apositionally static brake carrier which has two carrier arms whichproject over the outer edge of a disc brake, having brake shoes whichare arranged on both sides of the brake disc and which have in each caseone friction pad and one rear plate and which are supported displaceablyon the carrier arms, having a floating caliper which is guided axiallydisplaceably on the brake carrier and which engages around the brakeshoes and has an actuating device designed for pressing the brake shoesagainst the brake disc, having a spring arrangement which acts axiallyon the brake shoes in a brake release direction and which, after thebraking operation, assists in the setting of an air gap between thebrake shoes and the brake disc. The spring arrangement has at least onespreading spring which is fastened in altogether non-displaceablefashion in an axial direction to a carrier arm of the brake carrier, inthat the fastening is performed to a section of the carrier arm situatedover the outer edge of the brake disc, and in that the spreading springhas at least two spring arms which lie resiliently in an axial directionagainst the rear plates of the brake shoes.

US2014/0339026 A1 describes a spreading spring comprising a locking armwhich connects the spreading spring to a brake component, a retractionarm; and a preload device which is arranged between the locking arm andthe retraction arm, wherein the preload device comprises six or morespiral-shaped loops which store energy during a braking activation andwhich retract the brake components (brake pad) as soon as the brakingprocess has ended. A brake caliper in the form of a floating caliper,which is not a sliding caliper, is specified. This is suitable for apassenger vehicle but not for a commercial vehicle.

The invention is based on the object of further developing a disc brakeof the generic type such that, with the simplest structural means, theservice life in particular of the brake pads and of the brake disc islengthened, and the operating costs are altogether lowered.

A further object consists in providing a corresponding brake pad set.

Said object is achieved by way of a brake disc according to embodimentsof the invention.

The further object is achieved by way of a brake pad set according toembodiments of the invention.

A disc brake according to the invention for a commercial vehicle, havinga brake caliper which engages over a brake disc and which is in the formof a sliding caliper and which is fastened to a positionally staticbrake carrier and which has a central opening over the brake disc,comprises two brake pads which are arranged in the brake caliper andwhich are movable in opposite directions and which have in each case onepad carrier plate and one friction pad fastened thereto and of which anaction-side or application-side brake pad can be pressed against thebrake disc by way of an application device via at least one brakeplunger, and comprises at least one resetting device by means of whichthe brake caliper can be reset after a braking-induced displacement andrelease of the brake, wherein the resetting device has a spreadingdevice which engages on the opposite brake pads and which acts equallycounter to the respective application direction and which has resilientspreading elements which engage on the respective pad carrier plate. Thespreading device is arranged in the central opening, wherein thespreading elements engage, outside the friction pads, directly orindirectly on one side in the center region, or at least two abutmentregions arranged spaced apart from one another relative to the center,of the brake pads, wherein the abutment regions have in each case oneabutment surface and one bearing surface on which the spreading elementsare movably arranged.

By means of the design of the disc brake according to the invention,synchronous resetting of both brake pads and resetting of the brakecaliper when the brake is released are realized, wherein thesynchronicity relates both to the resetting forces and to the resettingtravels. Here, the resetting force acts counter to the respectiveapplication direction of the two brake pads, that is to say, in the caseof the reaction-side brake pad, toward the caliper rear section, and inthe case of the action-side brake pad, toward the caliper head, withgaps with respect to the brake disc being formed.

The spreading device expediently engages on the two brake pads at thepad carrier plates, specifically on the side facing toward the frictionpad fastened thereto or on the opposite rear side. To prevent jamming ofthe respective brake pad during the resetting movement, the spreadingelement engages either centrally on an upper exposed edge region of thepad carrier plate or symmetrically on two abutment regions to the rightand to the left.

A brake pad set according to the invention for the disc brake accordingto the invention has at least two brake pads with in each case one padcarrier plate and with a friction pad attached to the pad carrier plate,and has the spreading device as indicated above. The pad carrier platehave, outside the friction pads and on one side in the center region orat at least two abutment regions arranged spaced apart from one anotherrelative to the center, in each case one abutment surface and onebearing surface. This yields the advantage that multiple functions(axial and radial transmission of spring force, spring end guidance) arerealized in a small space.

In one embodiment, the spreading elements extend, proceeding from acentral region in the center of the opening, from the inside to theoutside to the abutment regions which are arranged spaced apart from oneanother relative to the center. It is also possible for the spreadingelements to extend, proceeding from a central region in the center ofthe opening, from the inside to the outside to the abutment regionswhich are arranged spaced apart from one another uniformly relative tothe center.

In this way, the spreading device is arranged in the center in the brakecaliper, wherein said spreading device is likewise arranged within anenvelope of a wheel rim of an associated wheel.

The two spreading elements are connected to one another in the center(in relation to the carrier horns). It is thus possible to ensure aspring force which is identical—in a small tolerance range—both on therun-in side and on the run-out side. Different spring forces betweenrun-out side and run-in side, which can lead to oblique wear, can beminimized by way of the unilateral engagement of in each case one springper pad.

A further embodiment provides that the central region of the openingextends to both sides of a virtual center of the opening approximatelyparallel to the plane of the brake disc over a length in a range from 30to 50% of a longitudinal axis of the opening. This yields anadvantageous adaptation of the spring forces.

In another embodiment, the spreading device has spring arms, of which ineach case two lie against an associated pad carrier plate, wherein thespring arms are connected to one another in the central region of theopening, which simplifies installation during assembly and maintenancework.

According to a further concept of the invention, the spreading devicehas oppositely acting spreading elements, preferably with elasticaction, in particular in the form of spring elements.

In the simplest form, a compression spring in the form of a helicalspring or leg spring is arranged between the two brake pads, wherein theleg spring is mounted in the center above the brake disc, for example ona pad retaining stirrup by means of which the two brake pads can bepushed under preload into a pad slot. In principle, with the use of ahelical spring, the attachment of the ends thereof to the pad carrierplates is sufficient to realize the spreading function to an adequateextent.

According to a further concept of the invention, the spreading device isoperatively connected not to the pad retaining stirrup but to the brakecarrier, which forms a counterbearing and in which the brake pads aremounted so as to be displaceable coaxially with respect to the brakedisc.

For this purpose, a retaining bow is provided which extends over thebrake disc in the circumferential region as far as brake carrier hornsof the brake carrier which delimit a pad slot on both sides, whichretaining bow is, in relation to the thickness of the brake disc,arranged in the center relative to said brake disc. The retaining bow isnot the pad retaining stirrup, but is an additional component which isnot attached to the pad retaining stirrup.

In one embodiment, the retaining bow may be attached to two mutuallyoppositely situated stirrups which are connected to the brake carrier,which permits simple attachment.

Alternatively, the retaining bow may be connected to at least the twobrake carrier horns of a pad slot, whereas the spreading elements, whichengage on the two brake pads, are connected to the retaining bow. Saidretaining bow thus forms a centering device which, in correspondencewith the brake carrier as a fixed bearing, may also be realized in someother way in terms of construction.

The retaining bow is preferably of C-shaped form in terms of itscontour, with a center limb which extends over the brake disc to theextent mentioned and with two end limbs which are angled in the samedirection as said center limb toward the brake carrier horns and ofwhich in each case one is fastened to a brake carrier horn of thecorresponding pad slot.

By way of the retaining bow to which the spreading device is fastened byway of its spring arms, automatic centering of the brake caliper after arelease of the brake, that is to say after the ending of a brakingprocess, is realized, wherein, by way of the thus fixed positioning ofthe spreading device, the brake pads are reset such that the brakecaliper is centered relative to the brake disc.

Furthermore, the spreading device is designed so as to act over theentire range of wear of the brake pads.

Since the points of force engagement on the brake pads change withprogressive wear, those functional parts of the spreading device whichmake contact with the brake pads are designed so as to be supported insliding fashion on the pad carrier plate of the respective brake pads.

To ensure secure retention of the spring limbs, or, in the case of adifferent design variant, of the spring arms, even under the action ofvibrations during driving operation, the spring arms are supported onthe upper edge of the pad carrier plate in relation to the base of thepad slot, likewise in sliding fashion as described above.

With corresponding design of the spreading device, it is moreoverpossible to dispense with the use of pad retaining springs, which, as isknown from the prior art, are fastened to the upper edge of the padcarrier plates and on which a pad retaining stirrup is supported, suchthat the respective brake pad is retained under preload in the pad slotof the brake carrier.

The structural realization of the spreading device according to theinvention may differ in terms of construction, wherein a major advantageemerges from the fact that it is possible to substantially dispense withmoving components, self-evidently with the exception of the resilientspreading elements which, for their function, perform a resilientdeflection.

The omission of moving parts that is now possible self-evidently has theeffect of lengthening the service life of the spreading device, as doesthe low number of components required, resulting, moreover, in extremelyinexpensive production and assembly.

In a further embodiment, each spring arm is formed, at the end, with afork-shaped spring end such that a support limb and a thrust-impartinglimb are formed, wherein the support limb lies movably on a bearingsurface of a narrow side of the pad carrier plate, and thethrust-imparting limb lies movably with pressure against an abutmentsurface of that side of the pad carrier plate which faces toward thefriction pad. In this way, an advantageous simultaneous functionality ispossible, specifically in that the spring arm can not only introducethrust forces via the abutment surface into the pad carrier plate but isalso guided displaceably in terms of its movements by the abutmentsurface and the bearing surface. It is furthermore possible for thebrake pad to be retained resiliently in its brake pad slot by way of thespring force that is introduced into said brake pad via the bearingsurface.

In one embodiment, the bearing surface may be arranged at an angle withrespect to a horizontal, wherein the angle lies in a range from 3 to15°.

In another embodiment, the abutment surface may protrude from the padcarrier plate or be formed into the pad carrier plate. An advantageousadaptation to different brake designs is thus possible.

Furthermore, a projection may be provided on the abutment surface,wherein the projection protrudes from the abutment surface into a slotbetween the support limb and the thrust-imparting limb. This can permitprecise guidance and improved transmission of force.

In an alternative embodiment, each spring arm is formed, at the end,with a spring end with a thrust-imparting limb, wherein thethrust-imparting limb is in contact with a support section of that sideof the pad carrier plate which faces toward the friction pad, whereinthe thrust-imparting limb, by way of an abutment section, lies movablywith pressure against an abutment surface of the support section of thepad carrier plate, and at the same time, by way of a bearing section,lies movably on a bearing surface of the support section of the padcarrier plate. This yields the advantage that two functions can berealized in the thrust-imparting limb, specifically transmission ofspring force in an axial and in a radial direction to the brake pad,with simultaneous guidance of the spring end and a saving of structuralspace and material.

In an alternative refinement, a thrust-imparting limb and a support limbat right angles thereto may be formed in the manner of an angled lug,which can reduce a structural space.

In one embodiment, it is preferable for the support section with theabutment surface and the bearing surface to be formed into the padcarrier plate. This is advantageous because it results in a saving ofspace and material.

The bearing surface of the abutment regions may be arranged at an anglewith respect to a horizontal, wherein the angle lies in a range from 3to 15°. Guidance of the spring end is improved in this way.

If the abutment surface protrudes from the pad carrier plate or isformed into the pad carrier plate, it is thereby possible to realize anadvantageous adaptation to different installation situations.

It is also possible for a projection to be provided on the abutmentsurface, wherein the projection protrudes from the abutment surface.More precise guidance of the spring end is thus possible.

A particularly advantageous embodiment can be made possible if theabutment regions have a support section which, with the abutment surfaceand the bearing surface, is formed into the pad carrier plate. Thisyields a saving of space and material.

In a particularly preferred embodiment, it is provided that the abutmentsurface runs so as to be offset, in a direction pointing away from thefriction pad, relative to that side surface of the pad carrier platewhich is equipped with the friction pad. This yields advantageousguidance of the spring end in the pad carrier plate together with atransmission of spring force in a small installation space.

-   -   The spreading device comprises two spreading elements, wherein a        first spreading element acts on a first pad and a second        spreading element acts on a second pad. The two spreading        elements are connected to one another in the center (in relation        to the carrier horns). It is thus possible to ensure a spring        force which is identical—in a small tolerance range—both on the        run-in side and on the run-out side. Different spring forces        between run-out side and run-in side, which can lead to oblique        wear, are minimized by way of the unilateral engagement of in        each case one spring per pad.    -   A uniform application of force by the springs on the action side        and on the reaction side, or on the thrust-piece side and on the        caliper side, can be realized by way of a flexible adjustment of        the center web. Furthermore, it is possible for slight incorrect        geometrical positioning of disc, pad and carrier to be        compensated by way of the flexible center web.    -   By way of the center web, it is possible for the active        resetting device to be easily positioned and held down by the        pad retaining stirrup. It is advantageously possible, during a        pad change, for the resetting device to be easily removed and        also exchanged.    -   Through the utilization of the entire pad slot between the        carrier horns, it is possible for use to be made of spreading        elements or springs with a relatively low spring rate in order        to impart relatively constant forces in the event of pad wear.        Owing to the long spring travels, the spring elements can be        tolerant with regard to spring forces. The spring travels lead        to a constant spring rate with low tolerances.    -   In a preferred design variant, only two springs are used.    -   The spreading elements may be formed from inexpensive and        geometrically flexible metal sheets.    -   As a result of the offset with different centers of rotation, it        is possible to replicate a relatively low spring rate (see        patent 4943—FIG. 2). There is advantageously no need for a large        number of windings (expensive, bulky).

Further advantages are:

Adjustability (of the centering)

Spring constants adaptable for each pad side, hence different forinside/outside and better adaptable to surroundings—within limits

Installation by way of center centering stirrup—compensates uneven forcebuild-up

Possible “active” caliper centering

Active pad suspension by way of “fork” on the end of the spider

Another embodiment provides that each spring arm is formed, at the end,with a spring end with a fastening section which, in its longitudinaldirection, is formed with an elongated hole which is a guide section forthe spring end of the spreading device. In this way, guidance duringrelative movements between the spring arms and the brake pads can beimproved, and a lift-off of the spring arms can be prevented.

Here, each fastening section may lie in each case on a bearing surfaceof a respective pad carrier plate, wherein the elongated holes of eachfastening section interact in each case with an abutment section of thepad rear plate. This yields a simple and effective construction.

For example, a pin fixedly connected to the pad carrier plate may havethe abutment surface, which interacts with the respective elongatedhole, of the pad carrier plate, wherein the bearing surfaces run in eachcase tangentially with respect to the brake disc and lie in a plane. Apin is an inexpensive, high-quality component, and can be easilyinstalled.

In one alternative, the elongated holes may form a guide opening whichinteracts with a contour of the pad carrier plate, wherein the contouris formed as a peg or a projection. Such contours can be easilyintegrally cast in the case of the pad carrier plate being produced as acast part. Here, it is possible for the contour to protrude from the padcarrier plate in an axial direction, in a radial direction and/or in atangential direction relative to the brake disc. In one variant, thecontour may also be formed in.

The contour offers a further advantage in that it can form a coding ofthe brake pads; for example, the application-side brake pads and therear-side brake pads may have different contours.

Alternatively, the contour may be a projection which forms a retainerfor a pad retaining spring. This is particularly simple.

In yet another embodiment, each spring arm is formed, at the end, with aspring end with a thrust-imparting limb, wherein the thrust-impartinglimb is in contact with a guide projection of that side of the padcarrier plate which faces toward the friction pad, wherein thethrust-imparting limb, by way of a first abutment section, lies movablywith pressure against an abutment surface of the pad carrier plate, andat the same time, by way of a second abutment section arranged at rightangles to the first abutment section, lies movably on a guide surface ofthe guide projection. In this way, simple spring ends can be used.

Here, in one embodiment, it is provided that the guide projection is ofcuboidal form and is arranged below an upper edge of a corner region ofthe pad carrier plate on the pad side thereof. This yields a compactarrangement.

A further embodiment provides that the spreading device has at least oneadditional resetting element which, in addition to the engagementpoint/the engagement points of the spring arms, engages at a furtherengagement point on the respective pad carrier plate of a brake pad.This is advantageous because, in this way, an assisted resetting of thebrake pads can be effected. A residual rubbing torque can thereby beprevented.

In one embodiment, the at least one resetting element may be fastened byway of one section, in a lower region of the pad carrier plate of anapplication-side brake pad on a thrust side of the pad carrier plate, toa retaining section, wherein the at least one resetting element isfastened by way of a further section in a lower region of a base plateof an application section of the brake caliper. In this way, it isadvantageously possible for a pulling force to be exerted on the brakepad by the resetting element.

Here, the at least one resetting element may be formed as a springelement with a central section, two spring arms and two fasteningsections with in each case one U-shaped lug, wherein the central sectionis fastened to the retaining section of the pad carrier plate, andwherein each spring arm is attached by way of the fastening section tothe base plate. This is a simple and compact design. The fastening tothe pad carrier plate can be performed quickly and easily for example bymeans of a claw-type connection to a pin of the pad carrier plate.

In a yet further embodiment, it is provided that the spreading devicehas at least one further additional resetting element, which is arrangedbetween a lower region of the pad carrier plate of the rear-side brakepad and a caliper rear section of the brake caliper. It is thus alsopossible for the rear-side brake pad to be reset, with assistance fromthe further resetting element, in order to prevent a residual rubbingtorque.

Here, the at least one further resetting element may be formed as a typeof leaf spring with a spring body with in each case one spring end,wherein one spring end is articulated, in a lower region of therear-side pad carrier plate on the thrust side thereof, on a holdingsection, and the other spring end is articulated on a fastening sectionof the caliper rear section of the brake caliper. In this way, a pullingforce can also be exerted on the rear-side brake pad.

In an alternative embodiment, the spreading device has at least twoadditional recesses elements which are situated opposite one another andwhich are of spring form, wherein each resetting element is fastened byway of one end to a section of the spreading device and/or to a padretaining stirrup, and wherein each free end of each resetting elementis, by way of in each case one thrust-imparting limb, in contact withthe respective pad carrier plate of each brake pad. This yields a simpleconstruction, wherein a thrust force is exerted on each brake pad by arespective setting element in order to assist a resetting of the brakepads.

For this purpose, it may be provided that the at least two additionalresetting elements are arranged in each case in an elongate intermediatespace between a friction pad and a pad side of the respective padcarrier plate, wherein the thrust-imparting limbs are in each case incontact with the pad side of the respective pad carrier plate and eachexert a thrust force on the brake pad in a direction pointing away fromthe brake disc. This is advantageous because the brake pads are notmodified, or are modified only to a very small extent.

In the case of a brake pad set, it is provided that the bearing surfaceof the abutment regions is arranged at an angle with respect to ahorizontal, wherein the angle lies in a range from 3 to 15°. A freerelative movement of spring arm and brake pad is thus possible.

It is advantageous if the abutment surface protrudes from the padcarrier plate or is formed into the pad carrier plate, because anextensive adaptation to different installation conditions is possible inthis way.

For example, one projection may be provided on the abutment surface,wherein the other projection protrudes from the abutment surface.

In another embodiment, the abutment regions may have a support sectionwhich, with the abutment surface and the bearing surface, is formed intothe pad carrier plate, in order to permit a space-saving construction.

The abutment surface may also run so as to be offset, in a directionpointing away from the friction pad, relative to that side surface ofthe pad carrier plate which is equipped with the friction pad.

For the guidance of the spring arms, the pad carrier plates may beequipped with at least one contour which protrudes from the respectivepad carrier plate or which is formed into the respective pad carrierplate. Thus, a movement travel can be easily defined, wherein a lift-offof the spring arms, for example in the event of vibrations, shocks etc.,can be prevented.

A further advantage arises in that the at least one contour (50) forms apad coding, by virtue of the application-side brake pad having adifferent contour than the rear-side brake pad.

In a further embodiment, the pad carrier plate of an application-sidebrake pad may be equipped with at least one resetting element. A codingmay be possible in this way also.

Accordingly, the pad carrier plate of a rear-side brake pad may also beequipped with at least one resetting element.

One embodiment of the brake pads provides that in each case one elongateintermediate space is arranged between a friction pad and a pad side ofthe respective pad carrier plate, whereby simple contacting for thespring arms of further resetting elements is realized.

Other objects, advantages and novel features of the present inventionwill become apparent from the following detailed description of one ormore preferred embodiments when considered in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 show in each case a detail of a disc brake according tothe invention in a perspective plan view;

FIG. 1A shows an enlarged schematic partially sectional illustration ofthe disc brake as per FIG. 1;

FIGS. 3-7 show further exemplary embodiments of the invention on thebasis of a detail of the disc brake, in each case likewise in adiagrammatic illustration;

FIGS. 8-28 show further exemplary embodiments of the invention, in eachcase as a detail of the disc brake in a perspective view;

FIG. 29 shows a perspective view of a further exemplary embodiment ofthe disc brake;

FIG. 30 shows a perspective view of a yet further exemplary embodimentof the disc brake;

FIG. 31 shows a perspective view of the spreading device of theexemplary embodiment of the disc brake as per FIG. 30;

FIGS. 32-33 shows enlarged detail illustrations of the spreading deviceas per FIG. 31;

FIGS. 34-41 show further exemplary embodiments of the invention, in eachcase as a detail of the disc brake; and

FIGS. 42-44 show views of a yet further exemplary embodiment of the discbrake having a spreading device with additional resetting elements.

The expressions “top”, “bottom”, “left”, “right” relate to therespective arrangements in the figures.

A “top side” and a “bottom side” of a brake pad 3 or of a pad carrierplate 4 always relate to the installation situation of the brake pad 3.Here, the bottom side of the brake pad 3 is situated closer in a radialdirection to a brake disc axis of rotation 2 a than the top side of saidbrake pad 3, as can be clearly seen for example from FIG. 3.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a part of a disc brake 100 for a commercial vehicle, havinga brake caliper 1 which engages over a brake disc 2. The brake disc 2has a brake disc axis of rotation 2 a (see FIG. 29). The brake caliper 1is attached, displaceably relative to the brake disc 2 axially in thedirection of the brake disc axis of rotation 2 a, to a brake carrier 6,for which purpose the brake caliper 1 is mounted on guide beams (notillustrated) which are connected to the brake carrier 6 which is held inpositionally static fashion on the vehicle.

The brake caliper 1 comprises an application section 1 a, a caliper rearsection 1 b and two tension struts 1 c. The application section 1 a runswith one side parallel to the plane of the brake disc 2 on one side ofthe brake disc 2. The caliper rear section 1 b is arranged on the otherside of the brake disc 2, likewise so as to run parallel to the brakedisc 2. The caliper rear section 1 b is connected to the applicationsection 1 a at in each case one end by way of in each case one tensionstrut 1 c. Here, the tension struts 1 c run substantially at rightangles to the application section 1 a and to the caliper rear section 1b.

The application section 1 a has an interior space in which anapplication device (not shown) of the disc brake 100 is arranged. Anopening of the interior space points toward the brake disc 2 and isclosed off by means of a plate, which is referred to as base plate 1 e(see FIG. 29).

In this arrangement, the application section 1 a, the caliper rearsection 1 b and the tension struts 1 c define, between them, a centralopening 41 which extends over the brake disc 2. The opening 41 has animaginary longitudinal central line which lies in the plane of the brakedisc 2 and which connects the imaginary centers of the tension struts 1c. Furthermore, the opening 41 has a further imaginary transversecentral line which connects an imaginary center of the applicationsection 1 a to an imaginary center of the caliper rear section 1 b. Thelongitudinal central line and the transverse central line intersect atan imaginary center point, which in this case is referred to as thevirtual center of the opening 41.

In the brake carrier 6 there are arranged brake pads 3 which, during abraking operation, can be pressed against the brake disc 2 at bothsides. Here, each brake pad 3 has a pad carrier plate 4 and a frictionpad 5 fastened to said pad carrier plate on the side facing toward thebrake disc 2, which friction pad is, during the functional operationthereof, that is to say during a braking operation, pressed against thebrake disc 2.

The brake pads 3 are accessible, for an exchange and for maintenance,through the central opening 41. Said brake pads can, through saidcentral opening 41, be inserted into their associated pad slots andremoved from said pad slots again. The pad slots are defined in eachcase laterally by brake carrier horns 25 (see FIG. 8).

Braking is performed by way of the application device arranged in areceiving space in the application section 1 a of the brake caliper 1,which application device has a brake lever which is positioned in a dome23 of the brake caliper 1. The associated brake pad 3, referred to asaction-side or application-side brake pad, is the first to make contactwith the brake disc 2 during a braking operation. During the furthercourse of the braking operation, reaction forces that occur cause thebrake caliper 1 to be displaced in the opposite direction, driving thereaction-side brake pad 3 along until the latter likewise comes intofrictional contact with the brake disc 2.

After a release of the brake, the two mutually oppositely situated brakepads 3 are, by way of a resetting device, released from the brake disc 2to such an extent that said brake disc runs freely relative to the brakepads 3.

The resetting device is composed of at least one spreading device 8,which engages on the mutually oppositely situated brake pads 4,correspondingly to the invention, so as to act equally counter to theapplication direction.

In the example shown in FIG. 1, the spreading device 8 is composed oftwo flat springs 9 which are of mirror-symmetrical form but otherwiseidentical and which are retained on a pad retaining spring 7 of therespective pad carrier plate 4, for which purpose, on each flat spring9, there is integrally formed a lug 11 which engages in positivelylocking fashion into a slot 10 of the pad retaining spring 7.

For this purpose, FIG. 1a illustrates an enlarged schematic partiallysectional illustration of the disc brake 100 as per FIG. 1. The sectionruns through a plane which is vertical in relation to FIG. 1 and whichruns through the brake disc axis of rotation 2 a.

That part of the flat spring 9 which is in contact with the pad carrierplate 4 is situated in a central section of the flat spring 9, and inthis case is referred to as thrust section 11 a. The thrust section 11 ais extended upward by the lug 11. In this example, the thrust section 11a lies against a clip element 7 a which is attached, for the retentionof the pad spring 7, to the pad carrier plate 4 in the central upperregion thereof. A section of the clip element 7 a extends through theslot 10 of the pad retaining spring 7. Said slot 10 is thus alreadyprovided and can be used for the positively locking engagement of thelug 11 of the flat spring 9.

That section of the clip element 7 a whose outer side is in contact withthe thrust section 11 a of the flat spring 9 lies with its inner sideagainst the pad carrier plate 4. In this way, the thrust force of thethrust section 11 a of the flat spring 9 is transmitted to the padcarrier plate 4. These explanations self-evidently also apply to theother flat spring 9.

Furthermore, FIG. 1a shows a pad retaining stirrup 28 (see also FIG. 8)which is arranged, over the brake pads 3, between the applicationsection 1 a and the caliper rear section 1 b in the transverse directionof the opening 41 or in the direction of the brake disc axis of rotation1 a and which is fastened to said application section and caliper rearsection. Here, the pad retaining stirrup 28 presses, by way of sectionsof its bottom side, against the clip elements 7 a and thus against thepad retaining springs 7, whereby the brake pads 3 are held in their padslots.

At the ends, the respective flat spring 9 is held in axially securedfashion on a stirrup 12 which is fastened to the brake carrier 6,wherein the two flat springs 9 are arranged spaced apart from oneanother. For an axial securing action, securing means 13 are provided onthe stirrup 12 so as to clamp the respective end of the flat spring 9between them.

During an application movement of the brake pads 3, the flat springs 9are correspondingly deformed, with a spring stress being built up, suchthat, after a release of the braking action, the brake pads 3 are pusheduniformly out of their braking position by the spring force that isprovided.

FIG. 2 illustrates a further exemplary embodiment of the invention, inwhich the spreading device 8 is formed in each case from a springstirrup 14, composed preferably of spring wire. Here, a spring stirrup14 of said type is pivotably fixedly held on each end region of the padcarrier plate 4 on the side facing toward the pad retaining springs 7,for which purpose there is arranged on the pad carrier plate 4 a bracket15 in which the ends of the spring stirrup 14 are, as viewed radiallywith respect to the brake disc 2, held rotatably so as to be offsetrelative to one another.

In FIG. 2, the bracket 15 comprises, for each end of the spring stirrup14, a rectangular mount section 151, 152, which mount sections areconnected by way of a connection 150 such that the mount section 151protrudes upward from the connection 150 and the mount section 152protrudes downward.

The bracket 15 may for example be formed in one piece with the padcarrier plate 4, for example by mechanical machining. It is alsopossible for the bracket 15 to be fastened to the pad carrier plate 4.

The bracket 15 may also be, for example, a rectangular plate such aswill be described in more detail further below (FIG. 24).

A spring stirrup 14 lies against in each case one associated brakecarrier horn of the brake carrier 6, specifically on the side situatedopposite the brake disc 2, such that, during an application movement ofthe brake pads 3, the spring stirrups 14 deform under stress. In theevent of a release of the brake, the brake pads 3 are pushed backcounter to their application direction by the spring force of the springstirrups 14, similarly to the exemplary embodiment as per FIG. 1.

FIG. 3 illustrates a further exemplary embodiment of the spreadingdevice 8, wherein here, the brake caliper has not been shown.

Said spreading device 8 is composed of two leaf springs 17 which areattached in each case stirrups 12 fastened to opposite sides of thebrake carrier 6, each of which leaf springs carries, on the free endsthereof facing toward one another, two scissor elements 16, of which oneis pivotably fastened to the action-side brake pad 3 and the other ispivotably fastened to the reaction-side brake pad 3.

The spring force to be imparted for the spreading action is, in thisdesign variant, realized by way of the leaf springs 17, which archradially outward during the application movement of the brake pads 3,and which straighten, during the release of the brake, correspondinglyto the spring action, with the attached scissor elements 16simultaneously being straightened and the brake pads 3 simultaneouslybeing spread apart.

FIG. 4 illustrates a further variant of the spreading device 8, whichhas two criss-crossing spring limbs 18 which are fastened articulatelyto a retaining bow 21. Said retaining bow is, similarly to the fasteningof the leaf springs 17 to the brake carrier 6, likewise retained onstirrups 12 which are connected thereto, which extends centrally overthe brake disc 2, in relation to the thickness thereof, over a part ofthe circumference. The retaining bow is not the pad retaining stirrup28.

The curved ends of the criss-crossing spring limbs 18 lie in each caseagainst an abutment 19 of the pad carrier plate 4, such that saidscissor-like construction spread in the event of an application movementof the brake, that is to say in the event of a movement of the brakepads 3 axially toward one another. Here, the spring limbs 18 arefastened to the retaining bow 21, such that the spring limbs 18 arepreloaded during the application movement of the brake pads 3, and thebrake pads 3 are spread apart from one another by said preload after arelease of the brake.

FIG. 5 illustrates a spreading device 8 which is composed of twoidentical spring arms 20 which are connected to one another in thecentral region in the longitudinal direction of the opening 41 andlikewise to a retaining bow 21 which is fastened to the brake carrier 6by way of stirrups 12.

Here, the spring arms 20 lie against two mutually oppositely situatedend regions of the pad carrier plate 4, specifically in an edge regionthat protrudes at the top side. The ends of the spring arms 20 arelikewise curved, such that sliding on the pad carrier plate surfaceduring the application and release of the brake is possible withoutproblems. In this case, too, spreading of the brake pads 3 after arelease of the brake is possible by way of the preload that is generatedduring the application movement.

In FIG. 6, each spreading device 8 is composed of an abutment limb 22which is connected rotatably to the stirrup 12 and which is formed inloop-shaped form from a spring wire and which likewise, like the springarms 20 as per FIG. 5, lies against the edge region of the respectivelyassociated pad carrier plate 4, wherein the two resilient abutment limbs22 of each side lie against those sides of the pad carrier plates 4which face toward one another.

Finally, FIG. 7 illustrates a further variant of the invention, which issubstantially similar to the embodiment as per FIG. 1. In this case,too, the flat spring 9 assigned to in each case one brake pad 3 engagescentrally on the pad carrier plate 4, preferably on an abutment 19,wherein, for this purpose, the flat spring 9 is equipped with aturned-out abutment stirrup 24.

For the central adjustment of both flat springs 9 in relation to thebrake disc 2, the flat springs 9 are fastened in axially displaceablefashion to the two mutually oppositely situated stirrups 12.

In the example shown in FIG. 8, the retaining bow 21 is of C-shapedform, having a center limb 26 which is arranged centrally in relation tothe thickness of the brake disc 2 and which extends in thecircumferential direction of said brake disc and which is adjoined atboth sides by in each case one angled end limb 27.

In FIG. 9, which shows a detail of a complete disc brake 100, whereasFIG. 8 shows merely the brake carrier 6 with the inserted brake pads 3,it can be clearly seen, as in FIG. 10, that the end limbs 27 areequipped, on the sides facing toward one another, with lugs 29, on whichthere are held pegs 30 which engage into bores 25 a (see FIG. 26) of thebrake carrier horns 25.

Here, the retaining bow 21 thus forms a centering device for the brakecaliper 1, as the brake carrier 6, to which the retaining bow 21 isfastened, forms a positionally static part which is mounted so as to bedisplaceable relative to the brake caliper 1, such that, after a releaseof the brake and a spreading movement of the spreading device 8, that isto say after the brake pads 3 have been pushed apart, the brake caliper1 is guided into a centered position.

FIG. 10 furthermore shows the brake pads 3 with the spreading device 8and the retaining bow 21 on their own.

In FIGS. 8 and 9, it can also be seen that a pad retaining stirrup 28that is held on the brake caliper 1 is supported on the pad retainingsprings 7 of the brake pads 3, and holds down and braces the retainingbow 21.

As can be seen from FIG. 10, the spring arms 20 of the spreading device8 are fixedly connected to one another in the central region,correspondingly to FIG. 5.

It can also be seen in FIGS. 9 and 10 that the spring arms 20 have, ineach case at their free end, support limbs 31 which are supported onthose edges of the pad carrier plates 4 which are assigned to the padretaining springs 7, by means of which support limbs the spring arms 20are prevented from departing from their position of abutment against therespective pad carrier plate 4 in the event of vibration movementsduring driving operation. Here, the support limbs 31 are braced betweenthe pad retaining springs 7 and the associated pad carrier plate 4,wherein the pad carrier plate 4 has a cutout (not illustrated) throughwhich the respective support limb 31 is guided. Tilting of the springarms 20 is thus prevented.

This can be seen in an enlarged illustration in FIG. 11, whichfurthermore shows a thrust-imparting limb 32, integrally formed incurved fashion on the spring arm 20, of a spring end 300, whichthrust-imparting limb lies against that edge surface of the pad carrierplate 4 which faces toward the friction pad 5, and whichthrust-imparting limb, as stated above, forms a tilting preventionmeans. Moreover, the friction pad 5 is prevented from striking thespring arm 20. Here, the support limb 31, which lies on a narrow side,facing away from the brake carrier 6, of the pad carrier plate 4, andthe thrust-imparting limb 32 form the prongs of a fork with a slot 301as which the spring end 300 of the spring arm 20 is formed. As alreadymentioned, the spring end 300 of the spring arm 20 in the abutmentregion with the pad carrier plate 4, that is to say the thrust-impartinglimb 32, is convexly curved in the direction of the pad carrier plate 4,in order to thereby ensure obstruction-free sliding on the pad carrierplate 4.

The support limb 31 of the spring end 300 lies by way of a bearingsection 31 a of its bottom side, facing toward the slot 301, on abearing surface 305 of the top side of the pad carrier plate 4. Thethrust-imparting limb 32 is in contact by way of an abutment section 32a, which points toward the pad carrier plate 4, with an abutment surface303 of the pad carrier plate 4. The abutment surface 303 is situated onthat side of the pad carrier plate 4 to which the friction pad 5 isapplied. Here, the abutment surface 303 is arranged above the frictionpad 5 in an end region of the pad carrier plate 4.

The bearing surface 305 on the top side of the pad carrier plate 4 maybe arranged at an angle 306 with respect to an imaginary horizontal,said angle having a magnitude in a range of for example 5 to 15°.

The bearing surface 305 forms a guide for the support limb 31 of thespring end 300 of the spring arm 20 during the movements thereof inmovement directions 302 (for example owing to wear compensation) and anabutment for said support limb in a direction toward the top side of thepad carrier plate 4.

Furthermore, the contact between the abutment surface 305 of the padcarrier plate 4 and the support limb 31 of the spring end 300 of thespring arm 20 forms a spring-loading means for the brake pad 3 in aradial direction. Furthermore, the pad carrier plate 4 and thus thebrake pad 3 are pushed downward into their pad slot, and spring-loaded,as a result of said points of contact with the support limbs 31 of thespring ends 300. If the spreading device 8 is fixed for example as shownin FIG. 1a by the pad retaining stirrup 28, it is also possible undersome circumstances for the brake pads 3 to be formed without padretaining springs 7.

The abutment surface 303 forms a guide for the thrust-imparting limb 32of the spring end 300 of the spring arm 20 during the movements thereofin movement directions 302 (for example in the event of wearcompensation) and an abutment for said thrust-imparting limb in adirection toward the pad carrier plate 4 parallel to a brake disc axisof rotation 2 a.

In an embodiment which is not shown, the abutment surface 303 mayprotrude from the pad carrier plate 4 or may be formed into the padcarrier plate 4, for example as a groove.

The abutment surface 303 and the bearing surface 305 may, as guidesurfaces, be provided with a particular surface treatment, for exampleby grinding, such that they have a low friction resistance.

It is also possible for a projection 304 to be provided which protrudesfrom the pad carrier plate 4 toward the spring end 300 into the slot301. In this way, the projection forms an additional guide for thespring end 300.

FIG. 12 shows an enlarged detail of the retaining bow 21 in the regionof attachment to the brake carrier horn 25, wherein the lug 29 lies on aplanar face side of the brake carrier horn 25. The peg 30 may be in theform of a rivet and plugged into a bore 25 a (see FIG. 26) of the brakecarrier horn 25. It is also possible for the peg 30 to be integrallyformed on the brake carrier horn 25, or to have already been fixedlyinserted as a separate component.

FIG. 13 shows the spreading device 8 as per FIGS. 8-13 as a detail.Here, at the free ends of the spring arms 20, respective spring ends 300are formed as bent thrust-imparting limbs 32. The thrust-imparting limbs32 each have the abutment section 32 a already indicated above in FIG.11. Furthermore, the thrust-imparting limbs 32 are in this caseequipped, on their bottom sides, with a respective bearing section 32 bwhich, for bearing contact as will be discussed in more detail below, isprovided with a suitable surface condition with a low coefficient offriction.

FIG. 13a shows, in this regard, an enlarged detail view of the endregion of a pad carrier plate 4 of a brake pad 3 together with athrust-imparting limb 32 of said type. The brake pad 3 has been insertedin its pad slot between two brake carrier horns 25, of which only one isillustrated here. As described above in conjunction with FIG. 12, an endlimb 27 of the retaining bow 21 has been attached to said brake carrierhorn 25.

The end region of the pad carrier plate 4 is in this case equipped witha support section 44 which is formed into the pad carrier plate 4, forexample by mechanical machining. The support section 44 has an abutmentsurface 45 and a bearing surface 46. The tolerance situation can also beconsiderably improved by means of this mechanical machining.Accordingly, the spacings of the center of the brake disc 2 or centerlimb and engagement surface on the pad carrier plate 4/brake caliper 1at the application side or thrust piece side can be kept very constant.

The abutment surface 45 runs parallel to, and so as to be offset withrespect to, that side surface of the pad carrier plate 4 which isequipped with the friction pad 5, wherein the abutment surface 45 isspaced apart from said side surface in the direction of the brake discaxis of rotation 2 a, that is to say axially, by an axial depth of theabutment surface 46.

The thrust-imparting limb 32 is arranged in the support section 44 andis in contact, by way of its abutment section 32 a, with the abutmentsurface 45. At the same time, the thrust-imparting limb 32 lies by wayof its bearing section 32 b on the bearing surface 46. Thethrust-imparting limb 32 is thus, during its movement, guided by thesupport section 44 as a result of its contact therewith. The abutmentsurface 45 and the bearing surface 46 may, by way of machining, beprovided with particular friction characteristics for said movement.

Furthermore, the pad carrier plate 4 and thus the brake pad 3 are pusheddownward into their pad slot, and spring-loaded, as a result of saidpoints of contact with the thrust-imparting limbs 32 of the spring ends300. If the spreading device 8 is fixed for example as shown in FIG. 1aby the pad retaining stirrup 28, it is also possible under somecircumstances for the brake pads 3 to be formed without pad retainingsprings 7.

Whereas FIG. 14 shows a detail of the attachment region of the retainingbow 21 on the brake carrier horn 25 in an enlarged view. Here, as atilting prevention means, a retaining plate 40 is provided which isfastened to the center limb 26 and against which the pad retainingstirrup 28 lies.

By contrast to the exemplary embodiment shown in FIG. 13, the lug 29 isnot angled relative to the end limb 27 but rather is formed by said endlimb so as to have the same profile, by way of corresponding shaping ofthe retaining bow 21.

A similar design variant to this is illustrated in FIG. 15, in which,however, the securing of the end limb 27 or of the lug 29 is realized byway of a nut 33 which is screwed onto a threaded peg of the brakecarrier horn 25 and which holds the lug 29 on the brake carrier horn 25.

In FIG. 16, a support lug 34 is angled oppositely to the end limb 27 ofthe retaining bow 21, which support lug lies on the face side of theassociated brake carrier horn 25 and, similarly to the support limb 31as per FIG. 11, forms a radial securing means for the retaining bow 21and thus for the spreading device 8.

A further variant of the fastening of the retaining bow 21 to the brakecarrier horn 25 can be seen in FIG. 17, which illustrates an enlargeddetail of the corresponding region of the brake carrier 6.

Here, in this case, the end limb 27 is, at the end side, angled so as tobe approximately parallel to the center limb 36 and is plugged onto thepeg 30 that is fastened in the brake carrier horn 25.

FIG. 18 illustrates a design variant of the spreading device 8 in whichthe spring arms 20, of which the end section of a spring arm 20 isillustrated, performs both the function of the retaining bow 21 and thespreading function.

For this purpose, the spring arm 20 is, in its end region, split in thelongitudinal direction, with a spring web 38 and an attachment web 37being formed. Here, the spring web 38, which is equipped with an angledlug 39 integrally formed on the end side, performs the spreadingfunction, that is to say is, during the braking-induced displacement ofthe brake pad 3, braced counter to the spring force, and, after therelease of the brake, forces the brake pad 3 into its end position,wherein the angled lug lies against the pad carrier plate 4 both in thebracing direction and in the radial direction, that is to say liesagainst the upper edge of the pad carrier plate 4.

Similarly to the embodiment as per FIG. 11, the angled lug 39 is dividedinto two different limbs and has a support limb 39 a and athrust-imparting limb 39 b lying at right angles to said support limb.In this example, the support limb 39 a and the thrust-imparting limb 39b are however formed not separately but rather so as to be connectedtogether in the form of the angled lug 39. The support limb 39 a is incontact, in a radial direction with respect to the brake disc axis ofrotation 2 a, with the bearing surface 46, wherein the thrust-impartinglimb 39 b is in contact, in an axial direction parallel to the brakedisc axis of rotation 2 a, with the abutment surface 45.

By contrast, the attachment web 37 is equipped, on the end, with a lug29 which has a peg 30, wherein the peg 30 is plugged into a bore 25 a(see FIG. 26) of the brake carrier horn 25 in order, as described, topermit centering of the brake caliper 1 after a braking process.

FIG. 19 shows the central region of a further exemplary embodiment ofthe spreading device 8, in which the spring arms 20 are formed from twocriss-crossing individual springs which are fixedly connected to oneanother in the central region. Here, a spring arm 20 of one individualspring lies against one pad carrier plate 4 and the other spring arm ofsaid individual spring lies against the other, opposite pad carrierplate 4, with a similar situation applying to the spring arms 20 of theother individual spring.

A fastening of the stirrup 12 similar to FIG. 5 is illustrated in FIG.20. Here, however, the securing means 13 for the retention of theretaining bow 21 has been dispensed with. Instead, the retaining bow 21is held in axially secured fashion on the stirrup 12 in particular byway of frictional engagement, though conceivably also by way of apositively locking action. Furthermore, the stirrup 12 is plugged intobores 25 a of the mutually oppositely situated brake carrier horns 25.

A construction that differs from this can be seen in FIG. 21, whichshows an enlarged detail of a fastening of the retaining bow 21.

Here, the stirrup 12 is in the form of a straightened bar and isfastened at the end to the retaining bow 21, the end limb 27 of whichadjoins the center limb 26 in an aligned manner, wherein the end limb 27has a fork-shaped end which engages over a pin 35 which is recessed intothe brake carrier horn 25.

In FIG. 22, likewise an enlarged detail in the region of a brake carrierhorn 25, it can be seen that a spring arm 20 of the spreading device 8is adjoined by a support lug 34 which lies against a support surface 36of the brake carrier horn 25 and which is supported both in a radialdirection with respect to the brake disc 2 and in an axial directionwith respect thereto.

Similarly to the embodiment as per FIG. 2, FIGS. 23 and 24 eachillustrate a design variant of the spreading device 8 which is composedof a spring stirrup 14 and an abutment limb 22, which are both inserted,at the end by way of in each case one fastening end 14 a, 22 a, into thebracket 15, wherein the latter is fastened to the pad carrier plate 4.

Here, the spring stirrup 14 and the abutment limb 22 are fastened,offset with respect to one another and on opposite sides, to the bracket15 and are supported at the other side on the brake carrier 6,specifically below the pad carrier plate 4 in the example shown in FIG.23 and on the brake carrier horn 25 in the example shown in FIG. 24.

The bracket 15 is in the form of an elongate rectangular plate with twolongitudinal sides 15 a, 15 b. Here, two diagonally opposite ends arerounded. The fastening end 14 a of the spring stirrup 14 is connected tothe bracket 15 eccentrically to the right at the top narrow longitudinalside 15 a shown in FIG. 24, whereas the fastening end 22 a of theabutment limb 22 is connected to the bracket 15 eccentrically to theleft at the bottom, other narrow longitudinal side 15 b.

The other ends of the spring stirrup 14 and of the abutment limb 22 runobliquely toward one another and are fixedly connected by a connectingbend 220.

The plate of the bracket 15 is in this case equipped with two fasteningholes 15 c for fastening purposes, for example by way of screws orrivets.

FIG. 25 shows a further exemplary embodiment which is of similarconstruction to that described in FIGS. 8 to 11, but with somedifferences.

The retaining bow 21 and the spring arms 20 are in this case formed inone piece, for example as a punched and bent part, and are fixedlyconnected in a central region by a common base section 42. The basesection 42 lies in the virtual center of the opening 41 and in a planewhich runs tangentially with respect to the brake disc 2.

From said base section 42, the center limbs 26 of the retaining bow 21extend to both sides in a downwardly bent manner over the brake disc 2,as shown in the exemplary embodiment as per FIG. 4, as flat stripsections almost as far as the tension struts 1 c which laterally delimitthe opening 41. At these points, the two center limbs 26 are bent towardthe application section 1 a of the brake caliper 1 and transition ineach case into an end limb 27.

Each end limb 27 has the lug 29 with the peg 30, similarly to theexemplary embodiment as per FIG. 8, but with the difference that the lug29 is not of widened form. Each end limb 27 runs with its lug 29 in aplane such that the lug 29 lies on the associated brake carrier horn 25.Here, the peg 30 is received in a bore 25 a (similarly to the situationshown in FIG. 26) and is fastened to the brake carrier horn 25. Thisself-evidently applies to both sides and to both brake carrier horns 25.

Furthermore, the base section 42 has, on its two longitudinal sides, ineach case one connecting section 43 bent downward through approximately90° toward the brake disc 2. Each connecting section 43 connects, oneach longitudinal side of the base section 42, in each case two springarms 20 to the base section 42 parallel to the imaginary longitudinalcentral line of the opening 41, such that an arrangement similar to thatin FIG. 8 is obtained. Here, each connecting section 43 lies in arespective plane which is arranged at approximately 90° with respect tothe plane of the base section 42 and which runs substantially parallelto the plane of the brake disc 2.

The spring ends 300 of the spring arms 20 are designed as illustratedand described in the exemplary embodiment as per FIG. 8 and in FIG. 11.

FIG. 26 illustrates a further exemplary embodiment, in which theretaining bow 21 is of wire-like form and has, for example, a circularcross section.

The retaining bow 21 comprises a central section 26 a in a centralregion of the opening 41. The central section 26 a is adjoined, on eachside, by a center section 26 which runs in each case in an arc in thedirection of the application section 1 a through an end limb 27 to therespective brake carrier horn 25. Each end limb 27 is then bent downwardthrough approximately 90° into in each case one fastening section 27 a.Each fastening section 27 a is fastened in a bore 25 a of each brakecarrier horn 25 of the pad slot of the action-side brake pad 3 and thusrealizes the retention of the retaining bow 21 with the spreading device8 in the brake carrier 6.

Here, the spring arms 20 are connected in each case in pairwise fashionby a connecting section 200 not in the longitudinal direction of theopening 41 but in the transverse direction of the opening 41. Eachconnecting section 200 is widened in a downward radial direction towardthe brake disc axis of rotation 2 a and has a recess 201. Each recess201 communicates with the outer contour of the retaining bow 21 and,here, has a semi-circular cross section which is upwardly open for thepurposes of receiving the retaining bow 21. The connecting section 200of the spring arms 20 thus arranged in pairwise fashion are arrangedwith a spacing 203 on the central section 26 a of the retaining bow 21,wherein the center of the central section 26 a is assigned to thevirtual center of the opening 41 and forms the center of the spacing203. A dimension of the spacing 203 corresponds in this case toapproximately one quarter of the longitudinal extent of the opening 41.The dimension of the spacing 203 may for example lie in a range of 30 to50% of the longitudinal extent of the opening 41 either symmetricallywith respect to the virtual center of the opening 41 or without arelationship to the virtual center of the opening 41. The spring arms 20may be connected to the retaining bow 21 for example by welding,pressing or both.

The spring arms 20 and the connecting sections 200 thereof are forexample formed in one piece as punched and bent parts composed of springsteel strip.

In the exemplary embodiment of FIG. 27, the retaining bow 21 is designedas in the embodiment as per FIG. 26. Here, however, the spring arms 20arranged in pairwise fashion in the transverse direction of the opening41, including their connecting sections 200, are of wire-like form. Theconnecting sections 200 are bent so as to form receptacles for theretaining bow 21. The spring arms 20 are in each case fixed upwardly bythe retaining bow 21, which is in turn pushed downward by the padretaining stirrup 28. With increasing pad wear, the connecting sections200 move toward one another in the direction of the center.

The ends of the spring arms 20 are in each case in the form of adownwardly bent fastening section 20 a. Each fastening section 20 a isreceived, from the top side, in a receiving hole 4 a on each end regionof a pad carrier plate 4. In this way, the spreading device 8 transmitsits spreading forces between each fastening section 20 a in theassociated receiving hole 4 a to the respective pad carrier plates 4.

FIG. 28 shows an exemplary embodiment in which the retaining bow 21 is,as in the embodiments as per FIGS. 26 and 27, of C-shaped form. Thespring arms 20 have spring ends 300 as per FIG. 11. Furthermore, thespring arms 20 are arranged in pairwise fashion in the transversedirection of the opening 41. Each pair of spring arms 20 is connected,at the other ends thereof, by way of a respective hood-type connector202.

Each hood-type connector 202 has a receiving opening, pointingdownwardly toward the brake disc 2, in the longitudinal direction of thecentral section 26 a of the retaining bow 21, which receiving openingcommunicates with the outer contour of the central section 26 a of theretaining bow 21.

The spring arms 20 which are connected in pairwise fashion to in eachcase one hood-type connector 202 are arranged with their respectivehood-type connector 202 on the central section 26 a. To fix the twospring arms 20 or spreading elements on the retaining bow 21, in eachcase two clamps are introduced, which are composed of half-shells andwhich, offset with respect to one another, clamp the spreading elementsto the retaining bow 21. To ensure the spacing 203, weld points areadditionally also formed between the components. Furthermore, clampsserve as spacers between the retaining bow 21 and spring arms 20. Thisis necessary in the embodiment as per FIG. 28 because the hardenedspring arm 21 cannot be placed with such a small radius on the retainingbow 21.

FIG. 29 shows a disc brake 100 in a perspective illustration with thebrake disc 2 and the brake disc axis of rotation 2 a.

A rotation arrow about the brake disc axis of rotation 2 a indicates amain direction of rotation for forward travel of a vehicle to which thedisc brake 100 is assigned. A run-in side ES and, opposite, a run-outside AS, of the disc brake 100 are defined in relation to the maindirection of rotation of the brake disc 2. Accordingly, the brakecarrier horns 25 on the run-in side ES are referred to as run-in-sidebrake carrier horns 25, and those on the run-out side AS are referred toas run-out-side brake carrier horns 25.

In this exemplary embodiment, the spreading device 8 is constructed insubstantially the same way as the spreading device 8 of the exemplaryembodiment as per FIG. 28. A difference in relation to the exemplaryembodiment as per FIG. 28 however consists in the fact that, in FIG. 29,the hood-type connectors 202 on both sides of the retaining bow 21 areconnected by way of in each case one longitudinal connector 202 a.Furthermore, the embodiment has no additional clamps. By contrast a FIG.28, the spreading device 8 is composed of one part with four spring arms20.

In preferred embodiments, a length of the spring arms 20, takentogether, in the longitudinal direction of the opening 41 corresponds toapproximately 60 to 95% of a pad slot length, particularly preferably 70to 80% of a pad slot length. The pad slot length is to be understood tomean the spacing of the associated brake carrier horns 25.

The spreading device 8 is composed of two spreading elements, which areconnected to one another in a longitudinal direction. The two spreadingelements are connected to one another centrally (in relation to thebrake carrier horns 25). It is thus possible to ensure a spring forcewhich is identical—in a small tolerance range—both on the run-in sideand on the run-out side. Different spring forces between run-out side ASand run-in side ES, which can lead to oblique wear, are minimized by wayof the unilateral engagement of in each case one spring arm 20 per brakepad. The central web between the two spreading elements may be connectedto the retaining bow 21 by means of a weld seam.

A uniform application of force by the spring arms 20 on the action sideand on the reaction side, or on the side of the application section 1 a(thrust-piece side) and on the side of the caliper rear section 1 b(caliper side), can be realized by way of a flexible adjustment of thecenter web, that is to say of the retaining bow 21. Furthermore, it ispossible for slight incorrect geometrical positioning of brake disc 2,friction pad 5 and pad carrier plate 4 to be compensated by way of theflexible center web.

By way of the center web, it is possible for the spreading device 8 asan active resetting device (ACR) to be easily positioned and held downby the pad retaining stirrup 28. It is advantageously possible, during apad change, for the spreading device 8 to be easily removed and alsoexchanged.

Through the utilization of the entire pad slot length between the brakecarrier horns 25, it is possible for use to be made of spreadingelements or spring arms 20 with a relatively low spring rate in order toimpart substantially constant forces in the event of pad wear. Owing tothe long spring travels, the spring arms 20 can be tolerant with regardto spring forces. The spring travels lead to a constant spring rate withlow tolerances.

In one design variant, use may be made of only two springs.

The spreading elements, that is to say the spring arms 20, may be formedfrom inexpensive and geometrically flexible metal sheets.

As a result of the offset with different centers of rotation, it ispossible to replicate a relatively low spring rate (see FIGS. 2, 23 and24). It is advantageously the case that only a small number of windingsis required.

FIG. 30 shows a perspective view of a yet further exemplary embodimentof the disc brake 100. FIG. 31 shows a perspective view of the spreadingdevice 8 of the exemplary embodiment of the disc brake 100 as per FIG.30. FIGS. 32 and 33 illustrate enlarged detail illustrations of thespreading device 8 as per FIG. 31.

This further exemplary embodiment is of similar construction to theexemplary embodiment of the disc brake 100 as per FIGS. 28 and 29. It istherefore sought to discuss only the differences.

The spreading device 8 is in this case equipped with elongate fasteningsections 20 a on the spring ends 300 of the spring arms 20. Saidfastening sections 20 a are formed, in their respective longitudinaldirection, with an elongated hole 48 which serves as a guide section forthe spring ends 300 of the spreading device 8.

In the assembled state of the disc brake 100, the fastening sections 20a interact, by way of their elongated holes 48, in each case with a pin47, as can be clearly seen for example in FIG. 32. Here, the outersurface of the pin 47 has an abutment surface of the pad carrier plate4. A pin 47 is fixedly connected to the pad carrier plate 4, for exampleinserted into a bore, at each end of a pad carrier plate 4. Here, anend, protruding from the pad carrier plate 4, of the pin 47 extendsthrough the associated elongated hole 48 of the respective spring end300 of the spreading device 8. Central axes of the pins 47 run parallelto one another and perpendicular to the brake disc axis of rotation 2 a.The elongated holes 48 permit relative movements between the spring arms20 of the spreading device 8 and the brake pads 3, which move in thedirection of the brake disc axis of rotation 2 a. The spring forces ofthe spring arms 20 make it possible for the brake pads 3 to be releasedfrom the brake disc 2 and reset after a braking operation, as alreadydescribed above. The bore for the pin 47 is in turn arranged veryexactly relative to the center of the brake disc 2. The above remarksregarding tolerances in conjunction with FIG. 13a also apply in thisregard.

Here, the fastening sections 20 a lie in each case on a bearing surface4 c of the respective pad carrier plate 4. The bearing surfaces 4 c runtangentially with respect to the brake disc 2 and, in the case of eachbrake pad 3, lie in a plane.

The design of the spreading device 8 is illustrated in FIG. 31.

The spreading device 8 comprises two spreading elements with in eachcase two spring arms 20, a clamp and the retaining bow 21.

The hood-type connectors 202 are connected on both sides in each case toa connecting section 20 b which forms in each case an extension of thespring arms 20, and said hood-type connectors are bent into asleeve-shaped form around the central section 26 a of the retaining bow21. In this way, each hood-type connector 202 together with the twoassociated spring arms 20 is mounted rotatably on the central section 26a of the retaining bow 21, wherein the spring arms 20 are connected toone another by means of the hood-type connector 202.

The clamp has a central web, which is referred to here as longitudinalconnector 202 a, four bent-over lugs as securing elements 26 c, and fourhold-down means as widened portions 26 b, which are intended to push thespring arms 20 onto the pad carrier plates 4.

The widened portions 26 b lie, in each case at both sides at thetransition of the central section 26 a to the center limb 26 of theretaining bow 21, on the connecting sections 20 b of the spring arms 20.In this way, the widened portions 26 b prevent a lift-off of thehood-type connectors 202 from the central section 26 a. At the sametime, the widened portions 26 b form an axial stop for the hood-typeconnectors 202, with the spring arms 20 fastened thereto, in thedirection of the longitudinal axis of the central section 26 a outward,that is to say in each case outward from the center of the opening 41toward the tension struts 1 c (see FIGS. 30 and 33).

The respective two connecting sections 20 b of the spring arms 20 pointwith their free ends toward the center of the opening 41 and are in eachcase connected in their end regions to the securing element 26 c. Thesecuring element 26 c is composed of in each case two bent-over lugswhich are fixed in each case with one end in a groove 26 d in each caseone end region of the connecting sections 20 b. In this way, thesecuring elements 26 c serve to further secure the hood-type connector202 against release from the central section 26 a.

By contrast to the embodiment as per FIG. 30, only one clamp is requiredhere instead of four clamps. The bracing of the spreading elements isensured by means of the bent-over lugs as securing elements 26 c of theclamp, which are bent over during the installation process and engageinto the groove 26 d. The spreading element is thus secured such that itdoes not slip in the direction of the center and tilt toward the padcarrier plate 4.

By virtue of the fact that the center web (longitudinal connector 202 a)of the clamp is furthermore of continuous form, the clamp can also nolonger slip axially on the retaining bow 21. It is thus possible todispense with weld seams or further fixing means. The clamp additionallyalso serves again as a spacer (see FIG. 28).

FIG. 34 shows a perspective view of a further spreading device 8. FIG.35 shows an associated pad carrier plate 4 in a view of its pad side 4b. FIG. 36 illustrates an enlarged view of a thrust-imparting limb 32with a contour 50.

The embodiment of the further spreading device 8 is similar to theembodiment as per FIG. 5 and FIG. 13. By contrast thereto, the springends 300 of the spring arms 20 in this case have in each case onethrust-imparting limb 32 with a guide opening 32 c. The guide openings32 c respectively interact with a contour 50 which, in this case, isformed as a cylindrical projection in the form of a peg 51.

The contour 50 is also referred to as interference contour and is forexample molded as a peg 51 onto the pad side 4 b of the pad carrierplate 4. Required casting radii 51 a may in this case run so as to beoffset into the pad carrier plate 4. The peg 51 protrudes from the padside 4 b in the direction of the brake disc axis of rotation 2 a. Ineach case one peg 51 is provided at each corner, that is to say betweena projection 49 for the retention of the pad retaining spring 7 and aside edge. The abutment surface 45 is arranged around each peg 51.

The thrust-imparting limbs 32 are, during the installation process,mounted with their guide sections 32 c over the respective interferencecontour 50. Here, each peg 51 extends through the associated guidesection 32 c of the thrust-imparting limb 32. The thrust-imparting limbs32 are in contact, by way of their abutment sections 32 a, with therespective abutment surface 45 of the pad carrier plate 4.

In this way, during actuation of the disc brake 100, each guide section32 c can, with the thrust-imparting section 32, move laterally withrespect to the peg 51, wherein the guide sections 32 c thus guide eachspring arm 20 in a radial direction. However, in a radial direction,slipping of the spring arms 20 is prevented by means of positive lockingin both radial directions. Thus, vibrations and other disruptiveinfluences cannot impair the function of the system.

The guide sections 32 c are formed as elongated holes, wherein theelongated holes are preferably of involute form.

The contour 50 may also be of a form other than an interference contour.FIG. 37 thus shows a perspective view of a variant of the spreadingdevice 8 as per FIG. 34. FIG. 38 shows an enlarged view of thethrust-imparting limb 32 with the contour 50, which in this variant isformed as a prismatic projection 52 with a rectangular outline.

In FIGS. 34 to 38, the contour 50 is formed in an axial direction, thatis to say the contour 50 protrudes from the pad carrier plate 4 in adirection parallel to the brake disc axis of rotation 2 a. It is alsopossible for the contour 50 to be provided as an interference contour ina radial and/or tangential direction relative to the brake disc 2 orrelative to its brake disc axis of rotation 2 a.

FIG. 39 shows contours 50 as interference contours formed in a radialdirection. Here, projections 53 are formed on each upper corner of thepad carrier plate 4, on in each case one oblique bearing surface 4 c ofthe top side of the pad carrier plate 4.

FIG. 40 illustrates contours 50 in a tangential direction. Here,projections 54 are likewise integrally formed on each upper corner, butin each case on a side surface 4 d.

A further variant is shown in FIG. 41. In this variant, a contour 50 isapplied as a cuboidal guide projection 55 below an upper edge of acorner region of the pad carrier plate 4, on the pad side 4 b thereof. Alower side of the guide projection 55, as guide surface 55 a, is incontact with an upper surface of a second abutment section 32 d of thethrust-imparting limb 32. The guide surface 55 a runs approximately atright angles to the abutment surface 45 of the pad carrier plate 4.Here, the thrust-imparting limb 32 has no guide opening 32 c but is incontact, by way of its first abutment section 32 a (see also FIG. 13),with the abutment surface 45. This is contact in an axial direction,whereas the abutment section 32 d is fixed in a radial direction by theguide projection 55. The first abutment section 32 a lies at rightangles to the second abutment section 32 d, which is formed in a simplemanner by the upper side surface of the thrust-imparting limb 32. Theabutment section 32 d can thus move in a lateral direction relative tothe guide section.

Furthermore, the contour 50 may be designed in any form, and may also beof recessed or raised form. In the case of a recessed contour 50, it isaccordingly the case that the thrust-imparting limb 32 of the spring arm50 is designed with a suitable guide contour of the guide section 32 c.The number of provided contours 50 may vary depending on the embodiment.

The contour 50 may also form a pad coding. For example, theapplication-side brake pad 3 may have the pegs 51 as contour 50, whereinthe rear-side brake pad 3 has the prismatic projections 52.

FIGS. 42-44 show views of a yet further exemplary embodiment of the discbrake 300 having a spreading device with additional resetting elements.

FIG. 42 shows a perspective view of a thrust side 4 f of the pad carrierplate 4 of the application-side or inner brake pad 3 with a resettingelement 57. FIG. 43 shows a sectional view, in a plane running throughthe brake disc axis of rotation 2 a, of the disc brake with therear-side or outer brake pad 3 with a further resetting element 62. FIG.44 illustrates a variant of the spreading device 8 with attachedresetting elements 66, 67 in a sectional view in a plane, runningthrough the brake disc axis of rotation 2 a, of the disc brake with thebrake pads 3.

The thrust side 4 f of the pad carrier plate 4 is that side of the padcarrier plate 4 which does not bear a friction pad 5, and which is incontact either with the application device or with the caliper rearsection 1 b.

The resetting elements 57, 62; 66, 67 each provide assistance of theresetting of the brake pads 3 from the brake disc 2 after a brakingprocess. Here, the resetting elements 57, 62; 66, 67 engage with asection in a lower region on the respective pad carrier plate 4 inaddition to the engagement point(s) at the top side of the spring arms20, wherein said resetting elements are connected with a differentsection to a section positionally static relative thereto, for examplebrake caliper 1 and/or brake carrier.

For this purpose, the resetting element 57 in the embodiment as per FIG.42 is fastened, with a section in a lower region of the pad carrierplate 4 on the thrust side 4 f thereof, to a retaining section 56, whichin this case is formed as a pin or peg-like projection. Furthermore, theresetting element 57 is attached with a further section in a lowerregion of the base plate 1 e (see FIG. 29) of the application section 1a of the brake caliper 1.

Here, the resetting element 57 is a spring element with a centralsection 58, two spring arms 59 and two fastening sections 60 with ineach case one U-shaped lug 61. The central section 58 is connectedcentrally to the retaining section 56 by means of a clamping/claw-typeconnection. At each side, the central section 58 transitionssymmetrically into the respective spring arm 59. Each spring arm 59extends to the left and to the right from the central section 58 in alower region along the pad carrier plate 4, and is shapedcorrespondingly to the contour thereof. The ends of each spring arm 59are connected in each case to the fastening section 60. Each fasteningsection 60 is shaped such that the bends of the U shapes are alignedwith one another and lie in a tangential direction with respect to thebrake disc axis of rotation 2 a. That limb of the fastening sections 60which points in each case toward the base plate 1 e runs outward as alug 61 and widens so as to have in each case one fastening bore for thefixing, by means of existing screws of the base plate 1 e, to said baseplate.

The rear-side brake pad 3 is equipped with the further resetting element62, as shown in FIG. 43.

The further resetting element 62 is formed as a type of leaf spring witha spring body 63 with in each case one spring end 64, 65. One spring end64 is articulated, in a lower region of the outer pad carrier plate 4 onthe thrust side 4 b thereof, on a retaining section 56 a, for example aneyelet. The other spring end 65, with a suitable design, digs into afastening section 1 d of the caliper rear section 1 b of the brakecaliper 1.

In this way, the resetting elements 57, 62 each exert a pulling force inthe direction of the brake disc axis of rotation 2 a pointing away fromthe brake disc 2, whereby, after every braking process, the brake pads 3are acted on with a force for a resetting action in the lower region bythe resetting elements 57, 62 as well as by the spring arms 20 of thespreading device 8.

In the embodiment as per FIG. 44, two mutually oppositely situatedresetting elements 66, 67 in spring form, for example leaf and/or wiresprings, are fastened in each case with one end to the central section26 a of the retaining bow 21 of the spreading device 8. From saidfastening point, each resetting element 66, 67 extends downwardly in anarc in the direction of the brake disc axis of rotation 2 a as far asinto the region of a lower region of each brake pad 3. Each resettingelement 66, 67 has a free end with in each case one thrust-impartinglimb 66 a, 67 a, and is arranged in each case in an elongateintermediate space between friction pad 3 and the pad side 4 b of thepad carrier plate 4, wherein the thrust-imparting limbs 66 a, 67 a areeach case in contact with the respective pad carrier plate 4. In thisembodiment, the resetting elements 66, 67 each exert a thrust force inthe direction of the brake disc axis of rotation 2 a pointing away fromthe brake disc 2, whereby, after every braking process, the brake pads 3are acted on with a force for a resetting action in the lower region bythe resetting elements 66, 67 as well as by the spring arms 20 of thespreading device 8.

It is also possible for the resetting elements 57, 62; 66, 67 to beattached for example to the pad retaining stirrup 28 and/or to theattachment sections thereof.

The invention is not restricted by the exemplary embodiments describedabove. It may be modified within the scope of the appended claims.

It is for example conceivable that, in a further variant, which is notillustrated but which is easily imaginable, of the spreading device 8 asper FIGS. 30, 31, 32 or FIGS. 34, 37, the spring ends 300 are mountedwith the thrust-imparting limbs 32 over the projections 49 over the padretaining springs 7. In other words, the projections 49 extend throughthe guide openings 32 c, which are adapted correspondingly to theprojections 49, of the respective thrust-imparting limbs 32 of thespring arms 20, wherein the spring arms 20 are shaped correspondinglyfor this purpose.

LIST OF REFERENCE DESIGNATIONS

-   1 Brake caliper-   1 a Application section-   1 b Caliper rear section-   1 c Tension strut-   1 d Fastening section-   1 e Base plate-   2 Brake disc-   2 a Brake disc axis of rotation-   3 Brake pad-   4 Pad carrier plate-   4 a Receiving hole-   4 b Pad side-   4 c Contact surface-   4 d, 4 e Side surface-   4 f Thrust side-   5 Friction pad-   6 Brake carrier-   7 Pad retaining spring-   7 a Clip element-   8 Spreading device-   9 Flat spring-   10 Slot-   11 Lug-   11 a Thrust section-   12 Stirrup-   13 Securing means-   14 Spring stirrup-   14 a Fastening end-   15 Bracket-   15 a, 15 b Longitudinal side-   15 c Fastening hole-   16 Scissor element-   17 Leaf spring-   18 Spring limb-   19 Abutment-   20 Spring arm-   20 a Fastening section-   20 b Connecting section-   21 Retaining bow-   22 Abutment limb-   22 a Fastening end-   23 Dome-   24 Abutment stirrup-   Brake carrier horn-   25 a Bore-   26 Center limb-   26 a Central section-   26 b Widened portion-   26 c Securing element-   26 d Groove-   27 End limb-   27 a Fastening section-   28 Pad retaining stirrup-   29 Lug-   30 Peg-   31 Support limb-   31 a Bearing section-   32 Thrust-imparting limb-   32 a Abutment section-   32 b Bearing section-   32 c Guide opening-   32 d Abutment section-   33 Nut-   34 Support lug-   35 Pin-   36 Support surface-   37 Attachment web-   38 Spring web-   39 Angled lug-   39 a Support leg-   39 b Thrust-imparting limb-   40 Retaining plate-   41 Opening-   42 Base section-   43 Connecting section-   44 Support section-   45 Abutment surface-   46 Bearing surface-   47 Pin-   48 Elongated hole-   49 Projection-   50 Contour-   51 Peg-   51 a Casting radii-   52, 53, 54 Projection-   55 Guide projection-   55 a Guide surface-   56, 56 a Retaining section-   57 Resetting element-   58 Central section-   59 Spring arm-   60 Fastening section-   61 Lug-   62 Resetting element-   63 Spring body-   64, 65 Spring end-   66, 67 Resetting element-   66 a, 67 a Spring end-   100 Disc brake-   150 Connection-   151, 152 Mount-   200 Connecting section-   201 Recess-   202 Hood-type connector-   202 a Longitudinal connector-   203 Spacing-   220 Connecting bend-   300 Spring end-   301 Slot-   302 Movement direction-   303 Abutment surface-   304 Projection-   305 Bearing surface-   306 Angle

The foregoing disclosure has been set forth merely to illustrate theinvention and is not intended to be limiting. Since modifications of thedisclosed embodiments incorporating the spirit and substance of theinvention may occur to persons skilled in the art, the invention shouldbe construed to include everything within the scope of the appendedclaims and equivalents thereof.

What is claimed is:
 1. A disc brake for a commercial vehicle,comprising: a brake caliper which engages over a brake disc and which isin the form of a sliding caliper and which is fastened to a positionallystatic brake carrier and which has a central opening over the brakedisc, two brake pads which are arranged in the brake caliper and whichare movable in opposite directions and which have in each case one padcarrier plate and one friction pad fastened thereto and of which anaction-side or application-side brake pad can be pressed against thebrake disc by way of an application device via at least one brakeplunger, and at least one resetting device by which the brake calipercan be reset after a braking-induced displacement and release of thebrake, wherein the resetting device has a spreading device which engageson the opposite brake pads and which acts equally counter to therespective application direction and which has resilient spreadingelements which engage on the respective pad carrier plate, the spreadingdevice is arranged in the central opening, the spreading elementsengage, outside the friction pads, directly or indirectly on one side atat least two abutment regions arranged spaced apart from one anotherrelative to the center, of the brake pads, wherein the abutment regionshave in each case one abutment surface and one bearing surface on whichthe spreading elements are movably arranged, the spreading device hasspring arms, of which in each case two lie against an associated padcarrier plate, wherein the spring arms are connected to one another inthe central region of the opening, and the spring arms are connected toa retaining bow which is attached to the brake carrier.
 2. The discbrake as claimed in claim 1, wherein the retaining bow is attached totwo mutually oppositely situated stirrups which are connected to thebrake carrier.
 3. The disc brake as claimed in claim 1, wherein theretaining bow is connected to two brake carrier horns which delimit apad slot, wherein the retaining bow is of C-shaped form with twomutually oppositely situated end limbs and with a center limb.
 4. Thedisc brake as claimed in claim 3, wherein the end limbs have in eachcase one lug into which pegs of the brake carrier horns are inserted. 5.The disc brake as claimed in claim 1, wherein the spring arms and/or aretaining bow are/is supported in a radial direction on the brakecarrier.
 6. The disc brake as claimed in claim 1, wherein each springarm is formed, at the end, with a fork-shaped spring end such that asupport limb and a thrust-imparting limb are formed, wherein the supportlimb lies movably on a bearing surface of a narrow side of the padcarrier plate, and the thrust-imparting limb lies movably with pressureagainst an abutment surface of that side of the pad carrier plate whichfaces toward the friction pad.
 7. The disc brake as claimed in claim 6,wherein the bearing surface is arranged at an angle with respect to ahorizontal, wherein the angle lies in a range from 3 to 15°.
 8. The discbrake as claimed in claim 7, wherein the abutment surface protrudes fromthe pad carrier plate or is formed into the pad carrier plate.
 9. Thedisc brake as claimed in claim 6, wherein a projection is provided onthe abutment surface, wherein the projection protrudes from the abutmentsurface into a slot between the support limb and the thrust-impartinglimb.
 10. The disc brake as claimed in claim 1, wherein each spring armis formed, at the end, with a spring end with a thrust-imparting limb,wherein the thrust-imparting limb is in contact with a support sectionof that side of the pad carrier plate which faces toward the frictionpad, the thrust-imparting limb, by way of an abutment section, liesmovably with pressure against an abutment surface of the support sectionof the pad carrier plate, and at the same time, by way of a bearingsection, lies movably on a bearing surface of the support section of thepad carrier plate.
 11. The disc brake as claimed in claim 10, wherein athrust-imparting limb and a support limb at right angles thereto areformed in the manner of an angled lug.
 12. The disc brake as claimed inclaim 11, wherein the support section with the abutment surface and thebearing surface is formed into the pad carrier plate.
 13. The disc brakeas claimed in claim 1, wherein the spring arm is, in the abutment regionagainst the pad carrier plate, of convex form on the side facing towardthe abutment surface.
 14. The disc brake as claimed in claim 1, whereinat least those spring arms which are assigned to one brake pad have, atthe end, a spring web, which lies against the pad carrier plate, and anattachment web, which is connected to the brake carrier.
 15. The discbrake as claimed in claim 1, wherein each spring arm is formed, at theend, with a spring end with a fastening section which, in itslongitudinal direction, is formed with an elongated hole which is aguide section for the spring end of the spreading device.
 16. The discbrake as claimed in claim 15, wherein each fastening section lies ineach case on a bearing surface of a respective pad carrier plate,wherein the elongated holes of each fastening section interact in eachcase with an abutment section of the pad rear plate.
 17. The disc brakeas claimed in claim 16, wherein a pin fixedly connected to the padcarrier plate has the abutment surface, which interacts with therespective elongated hole, of the pad carrier plate, wherein the bearingsurfaces run in each case tangentially with respect to the brake discand lie in a plane.
 18. The disc brake as claimed in claim 16, whereinthe elongated holes form a guide opening which interacts with a contourof the pad carrier plate, wherein the contour is formed as a peg or aprojection.
 19. The disc brake as claimed in claim 18, wherein thecontour protrudes from the pad carrier plate in an axial direction, in aradial direction and/or in a tangential direction relative to the brakedisc.
 20. The disc brake as claimed in claim 19, wherein the contour isa projection which forms a retainer for a pad retaining spring.
 21. Thedisc brake as claimed in claim 1, wherein each spring arm is formed, atthe end, with a spring end with a thrust-imparting limb, wherein thethrust-imparting limb is in contact with a guide projection of that sideof the pad carrier plate which faces toward the friction pad, thethrust-imparting limb, by way of a first abutment section, lies movablywith pressure against an abutment surface of the pad carrier plate, andat the same time, by way of a second abutment section arranged at rightangles to the first abutment section, lies movably on a guide surface ofthe guide projection.
 22. The disc brake as claimed in claim 21, whereinthe guide projection is of cuboidal form and is arranged below an upperedge of a corner region of the pad carrier plate on the pad sidethereof.
 23. A disc brake for a commercial vehicle, comprising: a brakecaliper which engages over a brake disc and which is in the form of asliding caliper and which is fastened to a positionally static brakecarrier and which has a central opening over the brake disc, two brakepads which are arranged in the brake caliper and which are movable inopposite directions and which have in each case one pad carrier plateand one friction pad fastened thereto and of which an action-side orapplication-side brake pad can be pressed against the brake disc by wayof an application device via at least one brake plunger, and at leastone resetting device by which the brake caliper can be reset after abraking-induced displacement and release of the brake, wherein theresetting device has a spreading device which engages on the oppositebrake pads and which acts equally counter to the respective applicationdirection and which has resilient spreading elements which engage on therespective pad carrier plate, the spreading device is arranged in thecentral opening, the spreading device has spring arms, the spring armsare connected to a retaining bow which is attached to the brake carrier,and the spring arms are arranged in pairwise fashion in a transversedirection of the opening.
 24. A disc brake for a commercial vehicle,comprising: a brake caliper which engages over a brake disc and which isin the form of a sliding caliper and which is fastened to a positionallystatic brake carrier and which has a central opening over the brakedisc, two brake pads which are arranged in the brake caliper and whichare movable in opposite directions and which have in each case one padcarrier plate and one friction pad fastened thereto and of which anaction-side or application-side brake pad can be pressed against thebrake disc by way of an application device via at least one brakeplunger, and at least one resetting device by which the brake calipercan be reset after a braking-induced displacement and release of thebrake, wherein the resetting device has a spreading device which engageson the opposite brake pads and which acts equally counter to therespective application direction and which has resilient spreadingelements which engage on the respective pad carrier plate, the spreadingdevice is arranged in the central opening, the spreading device hasspring arms, the spring arms are connected to a retaining bow which isattached to the brake carrier, and respective ends of the spring armsare formed as a downwardly bent fastening section and the fasteningsection is received in a respective receiving hole of the respective padcarrier plate.